Irritable Bowel Syndrome (IBS) is the most common of the functional gastrointestinal disorders with primary symptoms of chronic abdominal pain or discomfort associated with altered bowel habits. IBS is characterized by stress-related symptom exacerbations and a high co-morbidity with affective disorders, in particular, anxiety. The current proposal is based on a disease model of IBS that emphasizes enhanced responsiveness and conditioning of stress and fear circuits in the central nervous system, and associated hypervigilance, stress-induced hyperalgesia, and altered autonomic responses to visceral sensation. Based on this model and the highly successful exposure treatments now used for anxiety disorders, we have designed and successfully piloted a unique cognitive behavioral treatment (CBT) for IBS. Traditional CBT treatments focus on decreasing general stress responses and increasing coping skills for life stress, and have shown only modest efficacy in IBS. We hypothesize that IBS symptoms can be more effectively treated by specifically changing responses to visceral sensations through decreasing interoceptive conditioned responses, and directing attention away from visceral stimuli. If our hypotheses are correct, we expect to see greater symptom improvements as well as normalization of altered physiological responses following this new CBT approach. We propose to address the following specific aims: 1) Do subjective outcomes differ between the two cognitive behavioral interventions with and without interoceptive exposure and directed attention, and an attention control treatment? 2) Are differential treatment responses accompanied by changes in perceptual and autonomic responses to visceral stimuli? And 3) Are differential treatment responses accompanied by normalization of altered regional brain activation in response to visceral stimuli? In separate studies we will compare CBT with interoceptive exposure and directed attention to tradition CBT (and a control condition) on outcome measures of symptom reduction, beliefs, visceral sensitivity (pain, discomfort, and fear responses to balloon distension), and central responses to visceral stimulation using functional magnetic resonance imaging (fMRI).